1Upload the AIFF audio files whose level you want to change.
2Set a gain in decibels or as a percentage — positive to boost, negative to bring it down.
3Run it; headroom is checked first, so a boost that would clip is flagged rather than silently squared off.
4Download the adjusted AIFF file.
Adjust AIFF Volume FAQ
How does Adjust AIFF Volume change the level?
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Concretely, the gain is applied to the PCM samples directly, so the change is exact and reversible; headroom is checked before writing so a boost clips nothing. You set a gain in decibels or as a percentage and it is applied uniformly across the whole file.
Will boosting the volume distort the audio?
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Only if it clips. Headroom is checked before the file is written, so a boost that would push peaks past full scale is flagged rather than silently squared off. If the recording is quiet because it is noisy, boosting raises the noise too.
Does the source format matter?
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It does. AIFF is Apple's uncompressed PCM format — the Mac-side equivalent of WAV, same size, same fidelity. That decides whether a gain change is an exact edit of the samples or has to go through a re-encode.
Anything specific to AIFF to know?
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Yes — AIFF is big-endian PCM where WAV is little-endian; the audio is equivalent, and the choice is really about which ecosystem opens it without complaint. Relevant if you plan to adjust the level more than once.
Should I use volume or normalisation?
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Use volume when you know exactly how much louder or quieter you want it. Use normalisation when you want a set of files to end up at the same perceived loudness — that is a measurement problem, not a fixed gain, and applying one when you meant the other is the usual mistake.
Can I adjust a whole batch to the same gain?
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Yes, though be careful what you are asking for: the same gain on files recorded at different levels keeps them at different levels. If you want them to match, normalise instead.
What can I upload to Adjust AIFF Volume?
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WAV, FLAC and AIFF, at any bit depth and sample rate up to and including 24-bit/192 kHz. Lossy files work in the same batch if you are mixing sources.
Is there a file size limit on Adjust AIFF Volume?
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Yes: free accounts process audio up to 200 MB per file — for uncompressed PCM that is roughly twenty minutes of CD-quality stereo, so it is a real limit here in a way it is not for MP3. If you are over it, converting WAV to FLAC first is the free fix — it is lossless and roughly halves the size.
Will Adjust AIFF Volume lower the quality of my AIFF audio files?
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No. Lossless audio is edited sample-exactly, so what comes back decodes bit-identically to what you would get doing the same edit in a desktop editor. You can repeat the cycle as many times as you like without accumulating any loss at all.
Can I run Adjust AIFF Volume on several AIFF audio files at once?
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Yes, though lossless files are large, so the batch is bound by upload bandwidth rather than by processing. Settings apply uniformly across the set.
Are bit depth and sample rate preserved?
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Yes, unless you change them deliberately. A 24-bit/96 kHz source stays 24-bit/96 kHz — nothing is silently downsampled to 16/44.1, which is the failure mode that makes a master unusable.
Does Adjust AIFF Volume cost anything?
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No. Adjust AIFF Volume is free with no account required, and nothing is added to the audio. Uploads are deleted from the workers shortly after the job finishes.
